Electric signaling.



R. A. PESSENDENL ELECTRIC SIGNALING. APPLICATION FILED IEB. s, 190?.

91 5,280, Patented Mar. 16; 1 909. I

ulk

Wm mm 814mm roz UNITED sTArE REGINALD A. FES'SENDEN,

F WASHIN G'jION, DISTRICT or COLUMBIA.

ELECTRIC SIGNALING.

No; 915,280. Specification of To all whom it may concern:

Be it known that I, REGINALD A. FE'ssEN- DEN, a citizen of the .UnitedStates, and a resid on, in the District of 'usefulImprovements inElectric Signaling, of which the following is a specification.

My inventionrelates to the art of electric signaling, and particularlyto receivers for wireless t'elegraphy, its primary object being toprovide a more reliable and sensitive means for receiving electricimpulses, especially electro-magnetic waves, and producing signalsthereby. r

In the-accompanying drawing Figure 1 is a diagram in partial sectionshowing appara tus for carrylnout my invention, and Fig. 2 shows'insection a modiiied form of the receiver tube. a

Vacuum tubes heretofore'used as receivers for Wireless telegraphy havnot been found sufficiently sensitive and pe itive in their action, andespecially for fee-b le impulses. I have experimentally discovered thatthe de-' fectsmay be overcome as by using an improved'differentialvacuum tube containing gases, especially those of the helium type andalso by using differentially acting circuits. The efliciency is furtherimproved by 30 an essential arrangement of the parts one form of whichis hereinafter specified. ,In Fig. 1 the'antenna 11 may be grounded asat12,-or not, and may beconnected to the conductor 19 in other.modifications. 1 gleferably tuned by any of the means Well own In thisart and may be used either with a secondary it as here shown. tenna is aso-called vacuum tube 13, which may be of any desired shape, and maycon-- tam any suitable gas such as hydrogen, nitrogen, helium, argon,neon, etc., the ones named of the helium group having been found esageous.

The tube is p ecially advant provide withterminals 14, 15, 16, of whichIntermediate terminal 14 is preferably made .-.extremely small andcomposed of iridium. I provide a source of voltage 17, which may beeither a continuous current source, or an alternating current source,and is hereipre'f erably shown as a high frequency alternator,

aving referably a equency approxi- .mately t e same as the equencyjofimpulses to.be received; his connected a potentiometer 18 and may have avariable inductance or resistance 22 also in circuit,

Letters Patent. Application filed February 8,1907. Serial No. 356,3

'nals Patented March 16, 1909. as.

*In this device one winding cylinder is metallie so as to short-circuitany number ofturns of .the wirevdesired. It will be understood on bothcylinthe leads, and

while on the msulating'cylinder the; whole length of wire is traversed,the metallic cylinder directly connects the initial point With the lastturn of wire wound thereon. The

conductors 19, 20 and 21 make adjustable contact with the potentiometer,and may contain variable resistances or inductances 23, 24 as shown. Theterminals of the tube l3n1ay be heated'by any suitable .means as forexample 14 is shown heated by coil 32 excited by battery 26 and havingin circuit the variable resistance or inductance 25, the heat beingprojected by a reflector 33. A screen 37 may envelop the terminal 16 anda reflector 38 around the upper end of the tube is preferably used inorder to direct the radiation througha lens 29, whence it impinges onselenium cell or bolometer'30 to thereby operate the indicatingmechanism such as the bell 31 having battery 27. in circuit. Other-,

wise tie signals caused byradiation from the upper end of thecell 13 maybe read directly,

or of course the bell may bereplaced by a galvanometer.

In operation the potential between elec-- trodes 14 and 15. is soarranged by means of the potentiometer that no. current will passbetween these terminals or only a sh ht and comparatively non-luminousone, w ile the reater current asses between 1 6 and 14. The potentialsere are so adjusted that when electro-magnetic waves strike the antenna11', the steady balanceof current is disturbed in the differentialvacuum tube 13, .and the luminous column is caused to pass, eitherintermittently or steadily betweenterminals 14 and.15, which a signal asabove described.

In the construction of parts I prefer to make the terminals 15 and 16 ofsuch matewith an oxid. equivalents barium or strontium.

' In'Fig.. 2 I have shown a different form of the tube, made in a.Yshape, and the termimay consist of mercury with central metallicprojection as 3.5 or. 36. In this case the mercury may'contain a smallpercentage of metallic calcium or its equivalents or po- 11o tassium orsodium with advantage. 4 The above described-apparatus has been ceiver,

found to act-as avery reliable and steady reitz'being a great.advantage, among" other things; to have the-discharge divertedandidischarge tube having a central terminal to an entirely new terminaland directly.

vunean's for shifting the prising a differentially acting discharge tubecharged passing ential governing circuits adap 125; path by the passageof signal impulses.

cause a' signal through a detecting instrument.

J Having thus "describ'ed'myinvention and illustrated itsuse, What Iclaim as new and "desire to secure by LettersPatengis the following:

,1. A receiver for electro-magnetic waves 4 comprising an exhausted tubecontaining gas 'of the helium group.

2. A-receiver for electro-ina gnetic wavescomprising a discharge tubewith several paths .of discharge acting differentially and path ofdischarge therein by the wavesreceived.

3. -A receiver for electric signaling comand connected differted to havetheir balance changed to shift the discharge withseveral-terminals,

A, A receiver for Wireless telegraphy com prising a discharge tube withseveral dis-' charge paths therethrough, means 0 by electro-magneticWaves to shift t e path such shifting of the discharge path.

5. A receiver for wireless telegraphy com rising a dischar e tube andmeans forexcitmg it, connecte ed to have their balance disturbed by the;passage of electro-magnetic waves to'shift by its incidental-effectsrather 5 than by changes in the current being diseerated receivingcircuit 0 difierentiallcircuits adaptand so causing I I therein to beshifted on receipt of transmitted impulses.

.to shift the discharge from one leg to the other, and indicating meansoperated by said shifting of the discharge. 3

7. A receiver for electrlc signaling compri'smg an electric dlschargetube, means to 1 annul or balance oh the efiective discharge in va paththerein, and means operated by the received impulses'to disturb thebalance and restore said discharge to produce a signal.

8. Areceiverfor-electric signals compris-. ing a discharge tube withseveral alternative paths of discharge, and means, comprising areceiving circuit operativelyconnected to a terminal of the dischargetube for shifting the path of the discharge therein on receipt of thetransmitted impulses 9. A receiver for electric impulses comprising adischar paths of disc eratively connected to a terminal ofthe dischargetube for altering etube with several alternative arge and meanscompr smga I the normal potentials betweenthe terminals 'the "path of thedischarge Signed at Brant Rock in the county of Plymouth and State ofMassachusetts this 6th'day of February, A. D. 1907-.

' REGINALD -A.. FESSENDEN.

Witnesses:

JEssrE E. BENT,

' ODELEINE DoLE'vrm;

